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TDK # CE-0381. Input: 5 Vdc. Outputs: -10 Vdc, -19 Vdc, -26 Vdc, -26 Vdc and 6 Vac w/ center tap. These ratings w/ loads. 1.23" x 0.9". Includes hook-up diagram.

Spec sheet available in PDF format.

Average Customer Review:

(16 Reviews)

Customer Comments

Average Customer Review:

(16 Reviews)

WLWilson from Kingsland, GA

Additional Information

1. Output V1 output must have a capacitor even if it's unused. V1 is used on the board as feedback for some regulation of output.

2. Outputs V2 and V3 can be made to have + outputs by reversing D3 and D4. Polarity of filter capacitor must be reversed also. If you only need one + output only that diode needs reversing. Diodes D3 and D4 are the two laying in parallel.

3. V1 cannot be converted to have a + output.

4. Adding up all of the loads from the spec sheet it appears that the unit provides about 360 mW. This means that any one load or combination should be limited to about 360 mW or at least until Q1 gets warm.
I've measured the DCR of the windings and it appears that the transformer can handle more current.

5. For more power output a transistor with better power capability may replace Q1. Q2 drives Q1 in a Darlington pair configuration. Just don't let the transformer get too warm.

6. It appears that the unit will handle input potential higher than +5 as specified. I don't know the characteristics of Q1 or Q2 so it's difficult to determine the maximum input. I wouldn't go above about 10 volts. Just keep the total load below 360 mW and Q1 cool.

6. I've drawn a diagram of the circuit and I'll send it to All Electronics. What they do with it is up to them.
Warren

A customer from Purcellville, VA US

Handy VFD power supply

The Japanese fellow was a little off base, describing the transformer as an integrated circuit. I reverse engineered the DC-32, and obtained this schematic: http://www.vitriol.com/images/tech/DC-32.gif.
The earlier reviewer was correct, the -10VDC output is in the feedback path, and requires a capacitor.

A customer from Somewhere

Cheap for what it does

the input voltage range of these things is greater than 5v. The ones I have can handle up to 12v, provided they're only lightly loaded. I'm not sure what their longevity would be at 12v, but they do work.

Also, the AC output voltage increases in porportion to the input voltage. Usefull if you need more than 6v.

The -10v output, unsuprisingly, does not vary

A customer from SUNNYVALE, CA US

Doesn't seem all that touchy

I hooked one of these up with 5v input, oversized capacitors (1000uF input, 47uF on the outputs) and the appropriate load resistors per the spec sheet. Current draw was 100ma. Pulled off the 6VAC load. Dropped to about 70ma. Pulled off the -19VDC load (leaving the cap). Dropped to about 53ma. Pulled off the -26VDC load. 31ma. Now, I pulled off the -10VDC load; current draw was 4ma. Pulled the caps off the -19V and -26V outputs. No change. (But keep reading...) Tracing out the circuit, it looks like a simple blocking oscillator consisting of a two transistors in a darligton driving a multi-winding ferrite transformer. There is a zener diode connected to the -10VDC output which will oppose the DC bias applied to the oscillator and thus throttle the oscillator when the -10VDC output becomes more negative (and of course unthrottle it when it becomes less negative). Simple, but surprisingly effective regulation. Now, I didn't spend a tremendous amount of time with it, so there may be conditions where it goes unstable and starts to fry itself. But as near as I can tell, as long as the -10VDC output isn't overloaded and has a proper filter cap on it, and the other outputs aren't overloaded (they don't even need to be connected), this little device works fine. Remove the -10VDC filter cap, though, and it will fry quickly (well over 200ma). Same if you overload the 10VDC, reverse the filter cap (this is a *negative* output, remember) or significantly overload the other outputs. A good input cap is probably also important (I never experimented with removing it). So all things considered, this thing could serve as an unisolated, reasonably well-regulated 5VDC-to-minus-10VDC converter using only two caps. [Thanks to EricJ for the pointer to the Japanese experimenter's web site, which got me started on working out circuit and performance details. Lotta good stuff on that site.]

A customer from Houston, Texas

Emitter follower

TO Bruce in Nevada City, CA
How about sharring your successful emitter follower circuit with the rest of us? Thanks, Bill

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